Allulose: What It Is, Is It Safe, Side Effects and Allulose vs Stevia

Allulose is a rare sugar that tastes like sugar but is barely used by the body. Chemically it is a close cousin of fructose, found in tiny amounts in foods such as raisins, figs and maple syrup, and made commercially from fructose. Most of it passes into the urine unchanged, which is why the FDA allows food labels to count it at 0.4 calories per gram and to leave it out of Total Sugars and Added Sugars. The FDA has raised no questions about several safety notices for its use in foods, small trials suggest it blunts the blood sugar rise after a sugary drink, and the most common complaint is stomach upset when people have a lot. Here is what allulose is, what the research does and does not show, and how it compares with stevia.

Peptide Labs sells supplements but no allulose products, and this article does not recommend any product. It is general information, not medical advice.

What is allulose?

Allulose, also called D-psicose, is a simple sugar with the same chemical formula as glucose and fructose but a slightly different shape. The FDA describes it as an epimer of fructose, meaning one part of the molecule is flipped. It occurs naturally in very small amounts in wheat, raisins, dried figs, molasses, maple syrup and brown sugar. Because those amounts are tiny, the allulose in foods and sweetener bags is made by exposing fructose to enzymes that convert it.

That small change in shape makes a big difference in the body. According to information the FDA reviewed, most allulose is absorbed from the small intestine and then passes out in the urine largely intact, and the rest is poorly fermented by gut bacteria. Allulose browns and caramelizes like sugar and adds bulk, so it is used in baked goods, ice cream, syrups and “keto” snacks where an intense sweetener alone would not work.

How the FDA handles allulose on labels

In a guidance document finalized in October 2020, after a draft in April 2019, the FDA said it would not object if companies leave allulose out of the Total Sugars and Added Sugars lines and use 0.4 calories per gram instead of the usual 4 for carbohydrates. The agency based this on evidence that allulose is virtually unmetabolized, contributes very few calories and does not promote tooth decay, because it does not drop dental plaque acidity to the level that starts dissolving enamel. The FDA noted that human evidence on its calorie value is limited.

Two practical points follow. A product sweetened with allulose can show zero or near zero grams of sugar while its carbohydrate number stays higher, so read both lines. And guidance documents are not binding rules; they describe the agency’s current thinking.

Is allulose safe?

In the United States, allulose is used under the GRAS (generally recognized as safe) process. The FDA has received several GRAS notices from manufacturers for allulose as a sugar substitute in certain foods and beverages and has responded that it has no questions about their conclusions under the intended uses. That is not the same as a formal approval, and it covers specific uses rather than unlimited amounts.

Europe has taken a different path. In June 2025, the European Food Safety Authority (EFSA) concluded that the safety of allulose as a novel food could not be established, because the company that applied did not supply the extra data EFSA requested on production, genetic toxicity and human studies. That verdict reflects missing data rather than evidence of harm, but it means allulose is not authorized as a novel food in the EU on that application.

So is allulose safe? For most adults, the evidence so far points to stomach effects as the main issue. No sweetener is right for everyone, though, and long-term human data are thin. People with diabetes who use glucose-lowering medicines, anyone who is pregnant or breastfeeding, and people with digestive conditions should talk with their clinician before using a lot of any new sweetener.

Allulose side effects

The most common allulose side effects involve the gut. In a 2018 Korean tolerance study in young adults, allulose caused significantly more diarrhea, bloating and abdominal pain than sugar, and severe symptoms, including nausea, headache and loss of appetite, appeared at the highest intakes tested. In a 2026 Chinese trial, 48% of 50 healthy adults reported stomach symptoms over 30 days, but they were mild, short-lived and mostly in the first three days. That trial also found a small drop in bone density scores in older participants in the higher-intake group, still within normal ranges, which the authors said needs checking in longer studies.

• Gas, bloating and loose stools: more likely with large servings or when several allulose foods are eaten in one day.
• Stacking with sugar alcohols: many low-sugar foods combine allulose with erythritol or maltitol, which have their own digestive effects.
• Children: research in children is limited, so ask a pediatrician first.

Stop and get medical care for severe abdominal pain, persistent diarrhea or signs of dehydration.

Allulose and blood sugar: what the studies show

A 2026 meta-analysis in the American Journal of Clinical Nutrition pooled 12 allulose trials and found that adding allulose to a meal or drink lowered the blood glucose and insulin rise afterward, with moderate certainty. It found no significant effect on HbA1c, fasting glucose, cholesterol or body composition. One of the larger single trials, in 30 American adults without diabetes, found a lower glucose peak 30 minutes after a sugar drink when allulose was added; three of its authors worked for an allulose manufacturer, and the researchers called the results pilot observations.

In plain terms, allulose seems to soften a single blood sugar spike, mostly in short lab tests, and there is no good evidence that it changes weight or long-term blood sugar control. If you use a glucose meter or take diabetes medicine, track how you respond and ask your care team. Using a low-calorie sweetener is one small lever; our guides on cutting back on sugar and constant hunger cover the bigger habits.

Allulose vs stevia

The allulose vs stevia question comes down to what you need the sweetener to do. Allulose is a bulk sweetener that behaves like sugar in recipes, but you need more of it, which is where stomach effects come in. Stevia is an intense sweetener: only high-purity steviol glycosides are accepted under GRAS in the US, while whole stevia leaf and crude extracts are not permitted as sweeteners. Because a pinch of stevia does the work of a spoonful of sugar, many stevia products are blended with fillers such as erythritol or dextrose. Our sibling guide to monk fruit, another intense sweetener, explains how those blends work.

Tips for reading allulose labels

• Check the ingredient list, not just the front of the pack: allulose is often paired with monk fruit, stevia or sugar alcohols.
• Compare Total Carbohydrate with Total Sugars to see how much allulose or fiber a product contains.
• Try a small serving first if your gut is sensitive.
• Remember that “no sugar” foods still carry calories from fat, protein and flour.

If you are changing how you eat while taking a GLP-1 medicine, protein and fiber usually matter more than the sweetener; see our GLP-1 eating guide.

Frequently Asked Questions

Questions about a label? Contact us or read our Buyer’s Guide. Follow the label and ask a healthcare provider before starting any supplement or making a big change to what you eat, especially if you take medicines. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Last reviewed October 2026.

Related guides: How to Stop Sugar Cravings: Why They Happen and What Research Supports, Monk Fruit Sweetener: Is It Safe, What’s in It and Monk Fruit vs Stevia, GLP-1 Diet: What Experts Recommend While on GLP-1 Medicines.